The registration system is using, the privacy issue is according to their statement.

About privacy issue of COSCUP conference, COSCUP Organization Team notify that “organizers and event personnel will not provide any attendee’s personal information to sponsors”. Thus your registration data will only use for promotion and questionare of COSCUP and local open source community events sponsored by COSCUP 2008 remained fund (will only sent by COSCUP Organization Team), and WILL NOT transfer to anybody else.